1. Field of the Invention
The present invention relates a connection structure of a flexible board arranged in a camera, and particularly to a connection structure of a plurality of flexible boards arranged one over the other.
2. Description of the Related Art
Japanese Patent Application Publication No. 11-84215 discloses a lens device provided with a zoom position detection device. The zoom position detection device comprises a cord plate rotating during zooming and a sliding brush slidably fixed to the cord plate. Thus, the sliding brush reads conductor patterns formed on the cord plate to detect a zoom position.
In such a lens device, a plurality of flexible boards are usually arranged one over the other. After the plurality of flexible boards are stacked on a base portion such that the board terminal portions of the respective boards may be aligned with each other, then the respective board terminal portions are joined together by soldering.
As a material of the base portion on which the flexible boards are mounted, a plastic material has been conventionally used. Small protrusions (for example, of which diameter is about 1 mm) for engaging with the flexible boards are formed on the base portion of plastic. The flexible boards are positioned by engaging this protrusion with the flexible boards positions.
On the other hand, as the lens device is made smaller, the base portion has become so thin as to be deficient in strength, and therefore, today, a base portion of metal is used. In using the base portion of metal, it is difficult to make a small protrusion for engaging with the flexible boards. As a result, as shown in FIG. 11, after flexible boards 1, 2, and 3 are stacked on a base portion 4, these boards are fastened to it at three positions by screws 5, 6, and 7 while aligning the position of a board terminal portion la with the position of a board terminal portion 2a, and aligning the position of a board terminal portion 1b with the position of a board terminal portion 3b. 
However, positioning and screwing of the plurality of flexible boards 1, 2, and 3 have been very difficult work to be done at the same time, thus resulting in very poor assembly performance.
The present invention has been achieved considering these situations, and has an object to provide a connection structure of flexible boards which permits efficient positioning and connecting of a plurality of flexible boards arranged one over the other in a camera.
In order to attain the above described object, the present invention is directed to a connection structure of flexible boards in which a plurality of boards are stacked on a base portion of a camera so as to be arranged in the camera, wherein: a pair of holes is formed in each of the flexible boards; a pair of pin elements to be inserted into the pair of holes is provided in a protruding condition in the base portion, in which a spacing between the pair of pin elements is larger than a spacing between the pair of holes, and one of the pair of pin elements has a groove formed on an outer periphery surface of a side thereof opposite to a side thereof that faces to the other of the pair of pin elements; and the plurality of flexible boards are fixed on the base portion in the state in which an inner periphery edge of each one hole of the plurality of flexible boards are fitted in the groove.
According to the present invention, after a pin element having a groove is inserted into one hole of a pair of holes formed in a flexible board, while the flexible board is being engaged with the groove of the pin element, another pin element is inserted into the other hole, thereby permitting the flexible board to be mounted on the base portion with the flexible boards positioned. By mounting a plurality of flexible boards on the base portion, the plurality of flexible boards are stacked on top of each other with the flexible boards positioned, and therefore the plurality of positioned flexible boards can be fixed at the same time by fixing at only one position by screwing. Thereby, it is made possible to improve the assembly efficiency of a camera using a plurality of flexible boards.